Pregnene-21-aldehydes, their derivatives and process thereof



United States Patent 0 PREGNENE-Zl-ALDEHYDES, THEIR DERIVA- TIVES AND PROCESS THEREOF Karl Pfister III, Westfield, N. 1., and William J. Leanza, Staten Island, N. Y., assignors to Merck & Co., Inc., Raliway, N. 3., a corporation of New Jersey No Drawing. Application April 30, 1952, Serial No. 285,313

19 Claims. (Cl. 260397.45)

This invention relates to novel cyclopentanopoly-hy- 2F drophenanthrene compounds having cortisone-like activity, and processes for the preparation of these products; more particularly, it is concerned with ,the new comd h ps 33 triketo l7a,21 dihydroxypregnene and hydrocortisone (A 3,20} diket'o-llfi,l7u,2l-trihydroxypregnene)have been found to befvery valuable in'the treatment of various diseases. This invention is concerned with the preparation of novel compounds having cortisone-like activity CHO wherein R is a substituent from the group consisting of Patented-May 19, 195.3

'ice

hydroxyl and keto. These compounds, A -3,l-l,2O-triketo 17oz hydroxypregnene Zl-aldehyde, herein also called cortisone-Zl-aldehyde, and A -3,2O-diketo-l1fi,17adihydroxypreguene-Zl-aldchyde, herein also called hydrocortisone-Zl-aldehyde, are found to have cortisonelike activity and desirable physical and chemical characteristics. For example, cortisone-Zl-aldehyde is about three times as soluble in water as is cortisone.

it is a further object of this invention to provide novel aldehyde addition products of cortisone-Zl-aldehyde and hydrocortisone-Zl-aldehyde such as the hydrate, diacetate, dimethyl acetal, and diethyl acetal. Another object is to provide processes for the preparation of cortisone-21-aldehyde, hydrocortisone-Zl-aldehyde, and derivatives thereof.

In accordance with our invention, it is now found that cortisone 21 aldehyde and hydrocortisone-Zl-aldehyde can be prepared by the following reactions: 1

H\ /OH CHO COH =0 (5:0 on L0 wherein R is a hydroxy or keto substituent and X is an acid anion.

In accordance with the foregoing flowsheet, a 2l-pyridinium salt derived from cortisone or hydrocortisone is reacted with a nitroso compound such as p-nitrosodimethylaniline to form the corresponding 21-nitrone derivative (I) which on reaction with acid forms the aldehyde (II). The aldehyde is conveniently isolated in the form of the glyoxal derivative or hydrate (III) which is readily formed in aqueous solution.

In the first step of our process a 21-pyridinium salt derived from cortisone or hydrocortisone is intimately contacted with a nitroso compound such as p-nitrosodi methylaniline in the presence of a Weak alkali such as an alkali metal bicarbonate to form the corresponding 21- m'trone derivative. This reaction is preferably effected employing a polar solvent such as ,an aqueous solution of a lower aliphatic alcohol, for example, aqueous methanol or aqueous ethanol, although solvents such as ethylene glycol or dioxane can also be used as solvent mediums. Usually, we prefer to employ the chloride or ptoluenesulfonate salts of the 2l-pyridinium compounds, or a mixture of these salts as the starting materials in our process, since these salts are readily and conveniently prepared.

In carrying out the first step of our process in accord- 7 about 24 hours.

pyridinium salt is dissolved in aqueous methanol, the pnitrosodimethylaniline and potassium bicarbonate are added and the reaction mixture is permitted to stand for After the reaction is completed, the solid nitrone can be recovered by filtration and if desired may be further purified by recrystallization from suitable solvents. f

The nitrone is readily converted to the corresponding aldehyde compound by suspending it in a suitable solvent such as a non-polar organic solvent and reacting itwith acid. For example, the nitrone can be intimately con tacted with aqueous hydrochloric acid in the presence of ether to form the desired aldehyde which is recovered as the free glyoxal or hydrate by concentrating the separated ether layer. Thus, when A -3,11,20-triketo-17a-hydroxy- 2l-pregnenyl-N-(p-dimethylaminophenyl) nitrone is reacted with an aqueous solution of hydrochloric acid in the presence of ether, A -3,11,ZO-triketod7a-hydroxypreg nene-Zl-aldehyde (cortisone aldehyde) is formed which under the reaction conditions forms the hydrate derivative, A 17a,21,2l trihydroxy-3,11,20-triketopregnene. Similarly, A 3,20 diketo 11fi,17a-dihydroxy-2l-preg- 'nenyl N (p-dimethylaminophenyl) nitrone forms A 3,20 diketo 11,3,17u. dihydroxypregnene-Zl-aldehyde (hydrocortisone aldehyde) which is isolated as the hydrate, A llfi,l7a,21,21 tetrahydroxy-3,ZO-diketopregnene.

The novel aldehydes oi the present invention and the hydrate or glyoxal derivatives thereof are readily con- The resulting solution was allowed to stand at room temperature for one day. The reaction mixture was .concen: trated to dryness under reduced pressure at 40 C. and the residue dissolved in 100 ml. of warm methanol and 50 ml. of water. p-Nitrosodimethylaniline (1.3 g.) and a solution of 2.0 g. of potassium bicarbonate in 30 ml. of water were added. The resultant reaction mixture was allowed to stand for one day.

The solid nitrone was collected, washed with water,

a and air dried to give 2.2 g. of orange crystals, 'M. P.

EXAMPLE 2 Preparation of A -3,11,20-triketo-1 7a-hydroxy-21-pregnenyl-N-(p-dimethylaminophnyl) nitrone EXAMPLE 3 Preparation of .A 3,11,20-triketo-1 7a-hydr0xy-21 preg verted to the corresponding aldehyde addition products.

'Thus, upon reaction A -17a,21,21-trihydroxy-3,11,20-triketopregnene with acetic anhydride in the presence of The pyridinium derivatives of cortisone and hydrocor tisone employed as starting materials in our process are conveniently'prepared by reacting cortisone or hydrocortisone with pyridine in the presence of p-toluenesulfonyl chloride. This reaction results in the formation of a mixture of 21-pyridinium chloride salt and the 2l pyridinium p-toluene-sulfonate salts which may be recovered and separated, if desired, by fractional ,crystallization from suitable solvents. Alternatively, the mixture of the pyridinium salts can also be employed as the starting material in our process. The preparation of 21-pyri- 'dinium salts derived from cortisone and 'hydrocortisoneis described and claimed in copending application Serial No. 285,329, filed April 30, 1952, now U. S. Patent 2,665,274, issued January 5, 1954.

Both cortisone-21-aldehyde and hydrocortisone-Zl-aL dehyde are found to be fully as active as cortisone acetate in glycogen deposition assay. v

Cortisone-21-aldehyde hydrate, tested by the granulation-inhibition test in rats, showed activity both locally and systematically. It appeared to be especially active systematically, since 1 mgm. daily subcutaneously produced 37.3 inhibition of the growth in granulation tissue.

When cortisone-Zl-aldehyde hydrate is administered to rats subcutaneously, l mgm. daily for 6 days, this compound had cortisone-like activity and produced some adrenal atrophy (23.6 mgm. mean adrenal weight compared to 34.2 mgm. for the controls) and involutionof the thymus (267 mgm. compared to 397 mgm.).

The following examples are presented as specific embodiments of our invention. 7

EXAMPLE 1 Preparation of A -3JLZO-triketO-I7a-hydr0Xy:2 ]-pregneny l-N- (p-dim'ethyilaminophenyl) nitrone nenyl-N- (p-dimethylaminoph enyl) nitr0ne An aqueous methanol solution of 2.96 g. of A -17a-hydroxy-3,11,ZO-triketopregnenyl-Zl-pyridinium p-tcluenesulfonate was treated with a solution of 2.9 g. of p-nitrosodimethylaniline and 0.52 g. of potassium bicarbonate in 24 ml. of water. The reaction mixture was allowed to stand at room temperature for six days. The solid was collected, dissolved in methylene dichloride and absolute ethanol. The solution was concentrated in vacuo and the process repeated to remove any water from the system. The residue was dissolved in methylene dichloride and precipitated in crystalline form with methanol to give 1.6 g. of an orange solid M. P. 1846 C. (d.).

Calc. for C29H3sN2Os: C, 70.70; H, 7.37; N, 5.64. Found: C, 71.02; H, 7.43; N, 5.48.

EXAMPLE 4 Preparation of .A -3,1],ZO-triketo-l7a-hydroxypregnene- 21 aldehyde and its isolation as the hydrate, A -I7a,- 21-21 trihydro xy-3,I1 ,ZO-triketopregnene 0.5 g. of A -3,11,2O-triketo-17a-hydroxy-21pregflenyl- N-(p-dimethylaminophenyl)-nitrone was shaken with- '50 ml. of 1 N hydrochloric acid and 250 ml. of ether for two hours. The ether layer was collected and washed successively with dilute hydrochloric acid, water, sodium bicarbonate solution and water. After drying over sodium sulfate the organic layer was concentrated to yield 45 mg. of A -17u,21,21=trihydroxy-3,l1,20-triketopregnene. The mother liquors on re-extraction with ether yielded an additional 40 mg. of product.

The A -17u,21,21-trihydroxy-3,11,2O-triketopregnene on recrystallization from aqueous acetone was found to have the following properties:

Melting p0int.--Losses water 100 C., sinters and darkens at ISO-185 C.

ROZali0n.--[of l +182 2% in methanol.

U. V. abs0rpti0n.)\ maximum at 2380, E% 411, E mol. 15,500.

Solubilities.66 mg./ 100 ml. water, 10% in methanol, 2% in chloroform on prolonged shaking.

Analysis.Calc. for Crud-1280s: Mel. Wt. 376.4. C, 67.00; H, 7.50. Found: C, 67.01; .H, 7.75.

On dehydration the hydrate can be converted to the free aldehyde form. V

, 5 EXAMPLE 5 A 3,20 diketo 115,171: dihydroxy 21 pregnenyl N-(dimethylaminophenyl)-nitrne A 115,170; dihydroxy 3,20 diketopregnenyl 21 pyridinium chloride (830 mg.), which may be prepared as describedin U. S. Patent 2,665,274, was dissolved in 5 ml. of methanol and 6 ml. of water and treated with 320 mg. p-nitrosodimethylaniline. When all the solid had dissolved, 0.17 g. of potassium bicarbonate in 1 m1. of water was added. The reaction mixture was allowed to stand at room temperature for 72 hours. The precipitated nitrone was collected and washed with a small amount of cold water and air dried to give 570 mg. orange-dark red solid, M. P. 1868 C.

Calc. for CzsHseOsNz: C, 70.70; H, 7.37 N, 5.69. Found: C, 69.77; H, 7.73; N, 6.03.

EXAMPLE 6 Preparation of 13 3,20 diketo 11 8,1711 dihydroxypregnerie-ZI-aldehyde and its isolation as the hydrate- A*-. 15,] 7a,21,21-Ietrahydr0xy-3,ZO-diketopregnene A 3,20 diketo 115,170; dihYdIOXy 21 pregnenyl-N-(dimethylaminophenyl)-nitrone (1.2 g.) was suspended in 50 ml. of l N hydrochloric acid and covered with 100 ml. ether. The mixture was shaken until all the solid had dissolved. The layers were separated and the aqueous layer shaken with three 100 ml. portions of ether. The ether layers were combined, washed with 2.5 N hydrochloric acid, water, dilute sodium bicarbonate solution and water and was then dried over magnesium sulfate and concentrated to dryness. The residue was dissolved in acetone; water added to the cloud point and the solution charcoaled. The solution was concentrated in vacuo to a small volume and the crystals collected and air dried to give 520 mg. of product, M. P. 150-170" C. U. V. data: max.=2420, E%=423, diene=0.50%, Em==15,250.

EXAMPLE 7 A 21,21 -dimethoxy-1 7a-hydr0xy-3,1 1 ,20-

. triketopregnene 200 mg. of A -17,21,21 tn'hydroxy 3,11,20 triketopregnene was dissolved in cc. of anhydrous methanolic-hydrogen chloride and allowed to stand for one hour at room temperature. 500 cc. of ether was added and then an excess of saturated sodium bicarbonate solution. The ether layer was separated, washed with sodium carbonate solution, water, dried over sodium sulfate and vacuum evaporated to a syrup which solidilied on scratching. Yield 100 mg. M. P. 135140 C. This was recrystallized by dissolving in 400 cc. ether, treating with activated charcoal, filtering, and evaporating to 5 cc. Recovered 70 mg. or me dimethyl acetal as fine needles M. P. 142 C., and rotation [a]D +176 EXAMPLE 8 A 21,21-diethoxy-17u-hydr0xy-3,11,20-triketopregnene The diethyl acetal was prepared from 200 mg. of 17a,21,21 trihydroxy 3,11,20 triketopregnene in a manner analogous to the dimethyl acetal.

Anal.Calc. for CzsHssOs: C, 69.42; H, 8.39. Found: C, 69.48; H, 8.52.

M. P. 77 C. (micro-block). (2% in methanol).

Rotation a] 13 165 6 EXAMPLE 9 2 g. of A -17a,21,21-trihydroxy-3,11,20-triketopregnene was dissolved in 15 ml. of acetic anhydride and 1 ml. of pyridine and allowed to stand for 2 days. To the resulting reaction mixture was added 20 ml. of 50% acetic acid. The solution was then evaporated under diminished pressure to a syrup. The syrup was triturated with 40 ml. of water until the gum' solidified. On filtering the triturated mixture, 2.15 g. of crude diacetate having a melting point of 130l50 C., was obtained. The crude product was dissolved in 30 ml. of amyl acetate, treated with activatedcharcoal and filtered. Concentration of the filtrate to about 7 ml. and cooling atforded 0.95 g. of the diacetate derivative as a white precipitate, melting at 168 C. Rotation ialn +99 (2% in methanol).

EXAMPLE 10 A 3,] 1,20-triket0-1 7u-hydr0xypregnene-21-aldehyde A sample of A -17a,2l,21-trihydroxy-3,11,20-triketopregnene was dehydrated by heating at 110 C. over phosphorus pentoxide under diminished pressure for eighteen hours. The resulting yellow product, A -3,11,20- triketo-17a-hydroxypregnene-2l-aldehyde, had a melting point of 210215 C. (dec.). The aldehyde has an absorption band at 4500 A. (Em 36) which is characteristic of decarbonyl compounds, such as methylglyoxal and glyoxal.

Anal.--Calc. for C21Hzs05: Found: C, 70.09; H, 7.52.

Various changes and modifications may be made in carrying out the present invention without departing from the spirit and scope thereof. Insofar as these changes and modifications are within the scope of the appended claims, they are to be considered as part of this invention.

We claim:

1. A 3,11,20 triketo 17cc hydroxypregnene 21 aldehyde.

2. A 3,20 diketo 115,170 dihydroxypregnene 2l-aldehyde.

3. A 17a,21,21 trihydroxy 3,11,20 triketopregnene.

4. A l15,17a,21,21 tetrahydroxy 3,20 diketopregnene.

5. A 21,21 dimethoxy 170: hydroxy 3,11,20 triketopregnene.

6. A 21,21 diethoxy 17a hydroxy 3,11,20 triketopregnene.

7. A 21,21 diacetoxy 17a hydroxy 3,11,20 triketopregnene.

8. A compound from the group consisting of A -3,l1,20- triketo 17 a hydroxypregnene 21 aldehyde, A -3,20- diketo 115,17 dihydroxypregnene 21 aldehyde, and the 21,2l-dihydroxy, the 21,21-di-lower alkoxy and the 21,2l-diacyloxy derivatives thereof wherein the acyl group is a lower fatty acid radical.

9. The process which comprises reacting A -17a-hydroxy 3,11,20 triketopregnenyl 21 pyridinium chloride with p-nitrosodimethylaniline, and reacting the resulting reaction product with hydrochloric acid to form A -17a-hydroxy-3, 1 1,20-triketopregnene-2 l-aldehyde.

10. The process which comprises reacting A -17a-hydroxy 3,11,20 triketopregnenyl 21 pyridinium ptoluenesulfonate with p-nitrosodimethylaniline, and re acting the resulting reaction product with hydrochloric acid to form A -l7a-hydroxy-3J1,20-triketopregnene-2laldehyde.

11. The process which comprises reacting a A -17ahydroxy-3,1l,20-triketopregnenyl-2l-pyridinium salt with a nitroso compound, and reacting the resulting reaction product with an acid to form A -17a-hydroxy-3,11,20- triketopregnene-Z l -aldehyde.

12. The process which comprises reacting A 11B,17w dihydroxy 3,20 diketopregriene 21 pyridiniurn chloride with p nitrosodirnethylaniline, and reacting the resulting reaction product with hydrochloric acid to, form 4 ll ,9, l7a-dihydroXy-3 ,ZO-diketopregriene-Zl -aldehyde. 7

13. T he process which comprises reacting a A -l 15,17 dihydroxy 5 3,20 diketopregnenyl 21 pyridinium salt with a nitroso compound, and reacting the resulting re action product with an acid to remix-11 1 5,l7 a-dihydroxy- 7 with an acid to form the corresponding 2l-aldehyde, and

recovering said aldehyde as the .2;l,2l-dihydroxy derivative.

16; A 3,11,20 triketo 17d hydroxypregnenyl- 2l-N(p-dimethylaminophenyl') -n'itronc.

17. A 3,20 diketo 11,8,1701. dihydroxypregnenyl- 2l-N-(p dirnethylaminophenyl)-nitrorle. 4 i

18. The process which comprises reacting a A -3,1l,20- triketo-17a-hydroxypregnenyl-2l-pyridinium salt with pnitroso-dimethylaniline to form Ar -3,1LZO-triketO-N hydroxypregnenyl-2 l -N- p-dimethylaminophenyl -nitrone.

l9. The process which comprises reacting a Af*- 3, 2 0- diketo 115,170; dihydroxypregnenyl 21 pyridinium salt with p-nitrosoclin1ethylaniline to form A -3 ,20-diket0-' 115,170: dihydroxypregnenyl 21 N dimethylaminophenyD-nitrone. r

References Cited in the file of this patent I UNITED STATES PATENTS Kendall Aug. 7, 195,1 Kendall, Dec. 4,1951 

1. $4-3,11,20-TRIKETO-17A-HYDROXYPREGNENE-21ALDEHYDE. 